Approved: First Rx for Spinal Muscular Atrophy

Spinraza (nusinersen) approved to treat spinal muscular atrophy (SMA)

(RxWiki News) The US Food and Drug Administration (FDA) has approved the first drug to treat spinal muscular atrophy (SMA).

Spinraza (nusinersen) was approved to treat spinal muscular atrophy in adults and children. SMA, a rare and often fatal disease, affects muscle strength and movement. Because this condition affects the neurons that control movement, it causes muscles to become weak and begin to waste.

Nusinersen is available as an injection and is to be administered into the fluid that surrounds the spinal cord.

“There has been a long-standing need for a treatment for spinal muscular atrophy, the most common genetic cause of death in infants, and a disease that can affect people at any stage of life," said Dr. Billy Dunn, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, in a press release. 

A trial of nusinersen looked at the percentage of patients who saw an improvement in their motor milestones, which included sitting, head control, rolling, crawling, the ability to kick while lying down, standing and walking. The trial assessed patients with SMA that started in infancy.

Forty percent of patients treated with nusinersen saw improvements in motor milestones, according to the FDA.

Additional studies were conducted, but these clinical trials did not have control groups. Their findings did, however, appear to support this treatment's effectiveness.  

Commonly reported side effects include upper respiratory infections, lower respiratory infections and constipation. Nusinersen can cause serious side effects, which include low blood platelet count and toxicity to the kidneys. 

Biogen of Cambridge, Massachusetts, markets nusinersen. Ionis Pharmaceuticals of Carlsbad, California, develops it.